Where should the two bridges be set in a 110cm long wire so that it is divided into three parts and the ratio of the frequencies are `3 : 2 : 1` ?

Options

A. 20cm from one end and 60cm from other end
B. 30 cm from one end and 70cm from other end
C. 10 cm from one end and 50 cm from other end
D. 50 cm from one end and 40 cm from other end

Answer

A

Explanation

`n_1:n_2:n_3=3:2:1`
`n prop 1/l`
`l_1:l_2:l_3=1/3:1/2:1/1=2:3:6`
`l_1+l_2+l_3=110`
`implies2x+3x+6x=110 implies x=10`
`therefore` the two bridges should be set at 2x i.e., 20 cm frmom one end and 6x i.e., 60 cm from the other end.